Method for the energy management in a domestic environment

ABSTRACT

Apparatus and a method for management of energy consumption by appliances connected to a powered network wherein a plurality of the appliances are each provided with a programmed electronic control system adapted to transmit and receive to and from other electronic control systems and a device for measuring total network power consumption, information from which the power consumption of the appliances on the network and the maximum power available from the network can be determined. Each control system adjusts the power consumption of its corresponding appliance in accordance with the information that it receives and the instructions with which it is programmed without need for a central control unit or user intervention.

FIELD OF THE INVENTION

The present invention refers to a method for the management of theelectric energy consumption in a domestic environment.

It is known that the theme of the home automation, i.e. of theintegrated management of different electric devices being present in ahome, is always increasing in interest.

DESCRIPTION OF THE BACKGROUND ART

The known home automation systems involve the presence of a centralsupervisor unit that usually provides to manage the different householdappliances. By controlling some “intelligent” sockets, that thereforecontrol the supply of the energy to the different household appliancesby means of ON/OFF type operations.

These known centralized supervision systems present some drawbacks.

A first type of drawback is due to the complexity of the control units,which, having to manage a plurality of different domestic apparatuses indifferent times and ways, must be of the programmable type; thisnecessarily implies that the user is forced to a complicated programmingactivity.

A second type of drawback is due to the poor efficiency of the controland supervision system, which, as said before, manages the electricsupply of different domestic apparatuses solely with ON/OFF typeoperations driven through the so called “intelligent” supply sockets;such control mode is clearly very elementary and approximate.

A third type of drawback is caused by the cost of the centralsupervision units which, because of its programmability, needs of asuitable user interface, composed typically by a keyboard and a display,and of an electronic control system with suitable elaboration and memorycapability (for example a personal computer).

OBJECTS OF THE INVENTION

The main aim of the present invention is that of resolving the citeddrawbacks of the known systems for managing the house electricappliances (represented, i.e., by household appliances such as washingor cooking machines), based on the use of supervision and control unitsof the centralized type.

Within such aim, the present invention strives to provide for anoptimized management method, that avoids to overcome the limits of theinstalled maximum power being established by the contract with theelectric energy supplier, and also allows to favour the use of differenthousehold appliances during time periods of reduced energy cost; thisinvention seeks similarly to show a method in which the optimizedmanagement of the energy can be obtained in a fully automatic way,without any action by the user.

These and other aims, that will appear clearer in the following, arereached according to the invention, by a method for the management ofthe electric energy consumption in a domestic environment incorporatingthe characteristics of the annexed claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics and advantages of the present invention will becomeclear from the following description and the accompanying drawings,which are supplied as a pure elucidatory and non limiting example,wherein:

FIG. 1 schematically represents a domestic electric plant, equipped withsome household appliances realized according to the present invention;

FIG. 2 represents, through a flow chart, the control system's generalmode for managing the electrical energy consumption according to theinvention;

FIG. 3a represents in schematic form a possible embodiment of anapparatus for the measure of the instantaneous electric energyconsumption in a home, of the type suitable for the aims of the presentinvention;

FIG. 3b represents a possible embodiment of an energy meter able toprovides, besides to the value of the current energy consumption,further useful information for the aims of the present invention;

FIG. 4 illustrates in schematic form the concept of “synergy” amongdifferent domestic electric appliances, that is a direct consequence ofthe system according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

According to the present invention, the overcoming of limitations of theknown management systems is obtained through the use of electricappliances able to dynamically self-adjust their own energy consumption,changing it continually with respect to the global energetic exigencies(variable during the day) of the domestic environment wherein they areto operate. In other words, according to the invention, these householdappliances are quipped with control systems presenting the followingmain features:

1. ability to receive through a suitable transmitting medium and asuitable electronic interface, within regular intervals, informationabout the instantaneous electrical energy consumption of the domesticenvironment into which the appliances themselves operate. Theseinformation are supplied by a suitable, external measuring apparatus;

2. ability to evaluate the electrical energy consumption informationwith respect to the available maximum power limits established by thecontract with the energy supplier;

3. ability to manage the electrical energy consumption with respect tothe peculiar functions of the electrical appliance and, where possible,to the functions of the other electrical apparatuses in the homeenvironment.

From the first cited feature, the need is evidenced of having a suitableinstrument for the measure of the electric power being absorbed by thedomestic environment. It is also evidenced the need of having anadequate communication system between the aforementioned measuringapparatus and the electric appliances, that are, according to theinvention, equipped with a dynamic self adjustment system of the energyconsumption.

From the second cited features the need is evidenced of equipping theappliance with a control system, being easily programmable with respectto the maximum power limits established by the contract between the userand the supplier of the electric energy.

From the third feature, finally, the necessity emerges of definingpriority rules among the different domestic appliances, in order toensure a dynamic distribution of the energy, being optimized in functionof the type of the household appliances that are active time after time,and in function of the importance of their role for the user's need.

In the following of the present description there will be shown firstlythe general method for optimizing and rationalizing the consumption ofthe electric energy in a domestic environment and, secondly, thepossible embodiments for satisfying the needs evidenced by the abovementioned three features.

In particular, the optimized management of the electric energy of thedomestic environment is obtained, according to the invention, by meansof the following two actions:

avoiding the overcoming of the fixed current absorption limits, i.e. toavoid the black-out due to the action of a power limiter;

promoting in a simple way the use of different household electricappliances during time periods in which the electric energy has areduced cost.

In the FIG. 1 a domestic electric plant is represented in a schematicway, wherein part of the loads (electric appliances LB, LS and FO),according to the present invention, are able to self-adjust their ownenergy consumption.

The electric energy is taken from an external distribution net RE (block14), through an energy meter CE.

The power supplied through the meter CE is, as it normally happens,limited by means of a power limiter LP (block 2) that limits theinstalled power, in agreement with the supply contract that, in the caseof the represented example, establishes a maximum power limit of 3 kWh.

Four electric appliances, being typically present in a domesticenvironment, are supplied through four sockets indicated with PR (blocks3, 6, 9 and 12):

a laundry washing machine LB with power absorption of 2 kWh, adishwashing machine LS with power absorption of 2.4 kWh, an oven FO withpower absorption of 2.8 kWh and an electric iron (block 13) with powerabsorption of 2 kwh.

The energy meter CE, the laundry washing machine LB, the dishwashingmachine LS and the oven FO are connected to the electric net by means ofa suitable electronic interface (blocks 1, 4, 7 and 10), with the aim ofallowing a reciprocal exchange of information, according to the presentinvention; in the case herein described as an example, this is obtainedthrough a known system of the carrier data transmission type, accordingto which said exchange of information is carried out through the sameelectric net, using a suitable bi-directional modem of the half-duplextype, that is a device able to exchange the information in the twodirections, but in different times.

The three household appliances LB, LS and FO, being represented in FIG.1, are furthermore equipped with a suitable control system, indicatedrespectively with SC1 (block 5), SC2 (block 8) and SC3 (block 11). Suchcontrol system, that in the following will be generically indicated withSC, is of fundamental importance for the aims of the present invention,because it allows the rationalization the electric energy consumptionaccording to the mode shown in the flow chart shown in FIG. 2, thatdescribes the general method through which, according to the invention,the energy consumption of an electric appliance is self-adjusted.

It has to be specified that the way of exchanging the information amongthe electric household appliances LB, LS and FO (the so-calledcommunication protocols), does not represent the finality of the presentinvention, which only supposes the existence, in the domesticenvironment, of a suitable communication means or “bus”, a suitabletransmission line (in the case described herein, the carrier datatransmission system) onto which the flow of information is managed bymeans of suitable rules (protocols). being in conformity with thespecific international standards in the matter of safety,electromagnetic compatibility and information exchange.

For example, a “domestic bus” that satisfies all the requirements of theaforementioned international standard is that known as EHS (EuropeanHome System), recently developed in the purview of the program Esprit ofthe European Community. Another “bus” that satisfies the aforementionedinternational standard and which can be conveniently utilized in thepresent invention, is that proposed by the US Company Echelon, knownwith the name of LON (Local Operating Network).

In FIG. 2 a flow chart is represented, that describes the way in whichthe control system SC of any single electric appliance, being realizedaccording to the present invention, is able to self-adjust its ownelectric energy consumption, in the respect of limits of the availablepower established by the supply contract.

In such FIG. 2, block 15 represents the communication element, accordingto invention, between the control system SC of any of the three electricappliances LB, LS and FO of FIG. 1 and a device that measures constantlythe total electric power being absorbed (for explicative and nonlimiting purposes, in FIG. 1 such a device coincides with the energymeter CE of the domestic environment, having suitable characteristicsthat will be described in the following).

As already said, block 15 implies the existence of a communication“bus”, that allows for the dialogue among the energy meter CE and thesingle electric appliances LB, LS and FO, in accordance with theinternational standards in the matter of safety, electromagneticcompatibility and information exchange.

Through block 15, the control system SC of each of the three householdappliances (LB, LS and FO) receives from the energy meter CE, withinregular time intervals (for example once any minute), the current valueof the total power PT being absorbed at that instant by different activeelectric appliances of the domestic environment.

Block 16 is a test block, through which the control system SC of each ofthe three electric appliances verify if the current value of the totalpower being absorbed by different household appliances is greater thanthe maximum one (Pmax), which is established by the supply contract(contractual power) and adjusted by means of the power limiter LP (block2 of FIG. 1).

If PT is greater than Pmax, then the control passes to block 17, and thecontrol system SC provides FOR reducing the energy consumption of therelevant electric appliance of a quantity being greater or equal to thedifference PT-Pmax; successively, through block 18, the control returnsto block 15, so that the control system SC can update the value of thetotal power absorbed by different active electric appliances of thedomestic environment.

If, coming back to block 16, PT it is minor or equal to Pmax, then thecontrol passes to block 19, that it is a test block through which thecontrol system SC verifies the power absorption state of the relevantelectric appliance.

If the appliance is in a normal operating conditions, i.e. if there hasnot been any previous reduction of the power necessary at that momentfor its normal operation, the control will pass again to block 15, foran updating of the total absorbed power.

On the contrary, if the control system SC has been previously obliged toreduce the energy consumption of the relevant electric appliance (block17), the control will pass to block 20, that will operate again anincrease of the energy consumption, but having care that the maximumpower quantity being added does cannot exceed the difference Pmax-PT.

Successively, the control will return again to block 15, through block18.

Blocks 17 and 20 therefore represent respectively the ability of thecontrol system SC of each electric appliance, to reduce or to lead tothe normality status the energy consumption required by some particularphase of the operating cycle, during which the electric appliance isfound to operate. Such ability depends, obviously, upon the degrees offreedom of the control system SC.

In the specific case of the household appliances LB, LS and FOrepresented in FIG. 1, where the greater part of the absorbed powerrelates to heating elements, we can think, for example, of fractionatingsaid power between more elements (i.e. at least two resistances), inorder to have the maximum energy absorption when all the heatingelements are supplied. In that case, for reducing or increasing theabsorbed power, it will be sufficient to deactivate or activate thesingle heating elements, according to the needs.

Thus, greater is the number of the heating elements, higher will be thenumber of possible regulations available for the control system SC andmore rigorous will be, as a result, the management of the energy.

Block 15 of FIG. 2 expresses, as said before, the interaction betweenthe energy meter CE and the household appliances (LB, LS and FO)equipped with a suitable control system SC, according to invention,being able to manage such interaction.

Such a block 15 supposes thus that the energy meter CE is able to send,within regular time intervals, through suitable transmission means(that, as said before, in the specific case of FIG. 1 are constituted bya carrier data transmission system) and with a standard exchange mode(e.g. protocol EHS or LON), the information relating to the total powerabsorbed by different active household appliances in the domesticenvironment.

The condition that the meter CE is able to talk directly with thehousehold appliances represents, as said, a peculiar case, being purelyexplicative and non limiting of the present description; such conditionis sufficient and desirable, being economic and showing goodrequirements for the standardization of the proposed method, but it isnot strictly necessary for the purposes of the present invention.

In fact, more in general, we can think to employ any measuringapparatus, even external to the meter CE, being able to measure thetotal power supplied and to send such information on a suitable “bus”,to which the different domestic electric appliances are connected,according to invention (a possible embodiment of such a measuringapparatus is represented in FIG. 3a and described in the following).

Coming back to FIG. 2, blocks 16, 17 and 20 imply, finally, theknowledge, from the control system SC of each electric appliance, of thevalue of the contractual power Pmax. Such value may be signalled to thecontrol system SC by using suitable hardware configuration means (e.g.configuration jumpers or switches) at the moment of the installation ofthe electric appliance, or, even better, may be made available on thecommunication bus by the energy meter CE itself (as will be describedreferring to FIG. 3b), so allowing to the control system SC of eachelectric appliance to configure itself.

The management logic of the energy consumption, expressed in the flowchart of FIG. 2 is enhanced with the concept of the priority managementbetween the different household appliances.

In fact, in the case in which the oven FO and the dishwashing machine LSof FIG. 1 are simultaneously active, the latter can decide automaticallyto let more energy to the oven, the cooking of the food being consideredprioritary if compared to the washing of dishes; as a consequence, thewashing machine will continue with the heating of the water only duringthe natural pauses of the heating of the oven.

In other words, it is possible according to the present invention, tolet more electric appliances to operate, which share all together anelectric power value being greater than that provided for the singledomestic load, without any black-outs. This result is obtained on thebasis of the consideration that the household appliances have differentoperative phases during which the electric current absorption aredifferent: therefore, by managing with cleverness the single operativephases and by knowing how much other “not intelligent” electricappliances are consuming, it is possible to operate in a “time sharing”mode, letting a plurality of electric appliances operative, without thatthis fact can cause the overcoming of the contractual power.

This supposes that each “intelligent” household appliance declaresconstantly, onto the communication “bus” being common with the otherappliances, its instant consumption of electric energy and/or aninformation that allows to such other appliances to know that such“intelligent” electric appliance is operating; such informationdelivered on the bus is advantageously represented by the priority levelof the electric appliance, established on the basis of possiblystandardized rules.

In the case in which an electric load is not equipped with a controlsystem SC, according to the present invention (as it happens, forexample, for the electric iron—block 13—of FIG. 1), then it will haveautomatically assigned the maximum priority, if compared to the otherhousehold appliances, due to the fact that the electric iron does nothave the ability to self-adjust its own energy consumption in relationto the global consumption of the domestic environment.

In FIG. 3a the blocks diagram is represented of an apparatus being ableto measure the total power supplied in the domestic environment and tosend such information on the communication “bus”. In such FIG. 3a twoblocks can be identified: block B1, being associated to the energy meterCE and to the power limiter LP, and block B2, relating to the apparatusthat constantly measures the total power absorbed by an ensemble ofactive household appliances, and sends within regular time intervals,said measures to the appliance itself, in particular to the householdappliances LB, LS and FO, that are able to take advantage of such aninformation in order to self-adjust themselves.

Such information is sent, as already exemplified, by means of thetransmission system with carrier system data transmission, i.e. throughthe same wires of the domestic electric net.

It appears therefore that the functions carried out by the apparatusmeasuring the total absorbed power should be embodied in the same meterCE, since the main function of the meter is that of carrying out thesame measure of the supplied power; however, considering that in most ofcountries of the world, an energy meter being able to talk with thedifferent household appliances is not presently available, it has to beconsidered, even provisionally, the presence of the aforementionedexternal apparatus B2.

Considering block B2 relating to such an apparatus measuring the totalabsorbed power, we can distinguish the following pans

an amperometer A, for the measure of the current;

a voltmeter V, for the measure of the voltage;

a control logic LC, for the global management of the measuringapparatus;

a stabilized supply AS, for the DC supply, at low voltage, of thedifferent active parts of the system;

an interface IN, for the information exchange by means of the carrierdata transmission system;

a filter FA, possibly of active type, for the necessary suppression ofinterference being generated by the carrier data transmission system.

The control logic LC, based on the use of a microprocessor, performs twofundamental functions: the measure of the active power absorbed by thehousehold appliances and the delivery of such information on theelectric line, by means of carrier data transmission system.

The measure of the absorbed active power is carried out by LC on thebasis of the signals sent by the two measuring instruments A and V, andtaking into account the value of the phase angle between voltage andcurrent. The power is calculated by the circuit on the basis of theeffective voltage values (from voltmeter V), of effective current (fromamperometer A), and of the value of the phase angle, obtained bymeasuring the elapsed time between the instant in which the voltage iszero and that in which the current is zero.

The transmission on the domestic “bus” of the measured value of theactive power, being absorbed by the domestic loads, is carried out by LCthrough the interface IN of FIG. 3a.

The interface IN of FIG. 3a is a complex one, because it must be able totalk with the control units LC and, in the meantime, must manage theexchange on the “bus” with the carrier data transmission system,ensuring the respect of the international standard on the electricsafety, the electromagnetic compatibility and the information exchange.

The interface IN of block B1 is not herein described in detail, becausethis is not, as already said, the finality of the present invention;such interfaces can be, in any case, of any known type: in the specificcase, it is supposed that said interface is of a kind similar tointerfaces IN (blocks 4, 7 and 10) of FIG. 1; as an example, suchinterfaces IN or IN1 may be realized through a bi-directional modem ofthe half-duplex kind, of the type ST 7537 by SGS Thomson, associated toa suitable microcontroller for the management of the informationexchange protocol.

In FIG. 3b the blocks diagram is represented of an energy meter that isable to supply all the information being necessary for an advantageousembodiment of the present invention. Besides the blocks alreadydescribed with reference to FIG. 3a, the following additional blocks arepresent:

an interface IN1, in order to allow the remote reading (telemetry) bythe firm that supplies the electric energy;

a clock OC, for the management of the instant time and of differenthourly fees;

a selector LP for the limitation of the maximum power which can besupplied (contractual power), on the basis of the supply contract agreedbetween the user and the supplier.

In this case, the main functions of the control unit LC of FIG. 3b,realized in a known way are the following:

possibility of continuously measuring the supplied active power and tosum the measures of the kWh of consumed energy (specific function of theelectric energy meter);

possibility of talking, upstream, with the nearest energy distributioncentral, through the system of remote reading (telemetry) based on thecarrier data transmission system;

possibility of differentiated management of fees in the different timeperiods, due to the presence of a local clock, which can be eventuallymanaged upstream through the carrier data transmission system (functionwhich is associated to the telemetry);

possibility of locally configure the maximum power supplied on the basisof the supply contract agreed between the user and the supplier;

possibility of talking, downstream, with the different householdappliances of the house, which are prearranged for receiving by anenergy meter, within regular time intervals (for example any minute),the following information:

a) measure of the total power supplied;

b) maximum value of the power supplied according to the supply contract;

c) value of the time;

d) fees associated to the different time periods.

The aforementioned information a), b), c) and d), supplied by an energymeter of the type described in FIG. 3b, allows, in a way in itselfknown, to a household appliances equipped with a control systemaccording to the present invention, to optimize the electric energyconsumption, so avoiding to exceed the maximum power limits fixed by thesupply contract, and favouring the use of the appliances during timeperiods in which the electric energy has a reduced cost.

In particular, the information a) and b) allow to manage, in a totallyautomatic way and according to the way expressed in the flow chart ofFIG. 2, the instantaneous consumption of energy, so avoiding the actionof the device (LP) that limits the maximum power which can be suppliedaccording the supply contract.

The information c) and d) allow to the different household appliancesequipped with the control system SC to automatically carry out theirfunction in connection with time periods in which the cost of the energyis reduced. Such type of performance can be set by the user through thesimple pressure of a button (energy-saving button associated to timeperiods with lower fees), without being necessary to indicate the starthour of the operation of the same household apparatus.

Another possibility is that of showing the operation start hour, bymeans of the rotation of a simple knob, the index of which can varywithin an interval of 24 hours, without the complication of setting up atimer with a suitable delay (delay timer) calculated with respect to thecurrent time; in that case, only the information c) is exploited,without the necessity of disposing locally, i.e. inside of a householdappliances, of a clock with the current time, being of difficultmanagement for the user (e.g. the necessity of update after everyblack-out) and of considerable cost.

FIG. 4 finally represents in a schematic form the concept of “synergy”among different household appliances, mainly used in order to avoid theexceeding of maximum power available for said loads.

Such a concept is a direct consequence of the high management capacityof the control system, according to the present invention, of thehousehold appliances equipped with the control system SC.

It is in fact possible that each domestic electric load, being able tooptimize the consumption and to reduce the costs using the informationsupplied by the energy meter, according to the present invention, isalso able to take advantage of any eventual other useful informationsent by other electric appliances onto the communication “bus”.

Such information can for example relate to measures associated todetermined sensors being present in particular appliances.

For example, the laundry washing machine LB, is equipped with a sensorthat measures the water hardness. This value can be shared on the “bus”,with a benefit for other interested electric appliances, such as thedishwashing machine, the coffee machine, the electric water heater, theelectric iron, etc.

Another example may be carried out with reference to an air conditionerCA which, being equipped with air temperature and humidity sensors, canshare on the “bus” the measure of these quantities, with a benefit fordifferent interested electric appliances, such as a refrigerator, alaundry washing machine, etc.

Other example can be made with reference to the home safety system,indicated with SS, that is equipped with sensors being able to detectgas leakage; also such information can be delivered on the “bus”, inorder to warn other eventual appliances about dangerous situations andallow the self switching-off of all those household appliances that cancause sparks.

A further example may be made with reference to some peculiar domesticelectric appliances, that can send on the “bus” information being usefulfor the user, that can be shown on a television set TV: for example, theoven FO can communicate the end of a cooking process, thewashing-machine LB the end of a washing process, a freezer the deadlinefor the maximum preservation period of a certain foodstuff and so on.

From the above descriptions the characteristics and advantages of thepresent invention are clear.

In particular, according to the present invention, it is possible toobtain the optimal management of the electric energy consumption in adomestic environment, without involving any complex programming actionby the user.

The scope of such optimization is that of preventing the exceeding ofthe power limits established by the supply contract, so avoiding thepossible black-out caused by the action of the power limiter (LP), andof favouring the use of the different household appliances during timeperiods in which the electric energy has a reduced cost. In particularit is evident that, being available domestic electric appliancesequipped with a control system (SC) having the previously describedautonomy characteristics, it is possible to rationalize the consumptionof the electric energy in a fully automatic way, without having toemploy complex and expensive centralized control apparatuses.

The sole condition for performing said rationalization of the energyconsumption, according to proposed method, is the presence of a devicethat measures the absorbed power, that is able to communicate with thecontrol system of each single “intelligent” domestic electricappliances.

The household appliances that are made “intelligent”, according to thepresent invention, can adapt its own operative cycles in function of theavailable current and, therefore, also according to eventual “notintelligent” electric appliances, to which a maximum priority isassigned; eventually, according to the present invention, can also beused to manage in a fully autonomous way the hour, so making unnecessaryan on-board clock.

Advantages are finally also evident, in terms of cost for the user, ifcompared to the known solutions (mainly in consideration of the factthat most of the electric appliances actually produced already comprisea microcontroller, the capability of which is not usually fullyexploited).

Another aspect of the invention that has to be underlined is the conceptof “synergy” between the different household appliances equipped withthe control system SC, based on the possibility of sharing theinformation associated to different sensors, being available on thecommunication “bus” of the domestic environment.

It is clear that numerous variations are possible for those skilled inthe art to the method described as an example, without departing fromthe spirit and the scope of the inventive idea. For example, the use ofthe above mentioned carrier data transmission system has been shown as apure example, because of its practical convenience, due to the fact thatit does not require the installation of any communication line and isthus compatible with the electric net of any domestic environment; it ishowever clear that other means can he utilized for the exchange ofinformation being necessary for the present invention, for example asimple cable with two wires, similar to the telephonic bight (that wouldbe the more economic solution), a coaxial cable, a system with radiowaves, a infrared radiation system etc.

What is claimed is:
 1. A method for managing energy consumption byelectrical appliances operatively connected to an electrical network,each of which presents an electrical load to a source of power that isalso connected to the network for supply power to the appliances,comprising providing each one of a plurality of said appliances with aprogrammed electronic control system, measuring the instantaneous totalconsumption of electrical energy from said power source with a measuringdevice, transmitting to each control system information from saidmeasuring device information which is a function of the instantaneoustotal consumption of electrical energy from said power source, andcausing each control system to adjust the load presented to said powersource by its corresponding appliance in response to the informationprovided thereto.
 2. A method, according to claim 1, wherein each ofsaid electronic control systems is programmed to adjust the loadpresented to said power source without user intervention.
 3. A method,according to claim 1, further comprising causing each control system ofan appliance to dynamically self-adjusting its energy consumption, as afunction of the energy consumption of other ones of said appliances. 4.A method, according to claim 3, further comprising causing each controlsystem of an appliance to dynamically self-adjusting its energyconsumption, as a function of the difference between the maximum energyavailable to the appliances and the instantaneous total energyconsumption of the appliances.
 5. A method, according to claim 3,further comprising causing the control system corresponding to eachhousehold appliance to reduce the energy consumption of itscorresponding appliance in response to the instantaneous total energyconsumption of the appliances approaching the maximum energy availableto the appliances.
 6. A method, according to claim 5, further comprisingcausing each control system to periodically compare the totalinstantaneous energy consumption with the maximum energy available tothe appliances.
 7. A method, according to claim 6, further comprisingcausing a control system to reduce the energy consumption of itscorresponding appliance by a magnitude equal to or greater than thedifference between the magnitude of the total instantaneous energyconsumption and the maximum energy available to the appliances inresponse to the total instantaneous energy consumption approaching themaximum energy available to the appliances.
 8. A method, according tothe claim 6, further comprising causing one of the control systems toincrease the energy consumption of its corresponding appliance by amagnitude equal to or less than the difference between the magnitude ofthe total instantaneous energy consumption and the maximum energyavailable to the appliances in response to the total instantaneousenergy consumption being less than the maximum energy available to theappliances and said one of the control systems having previously reducedthe energy consumption of its corresponding appliance.
 9. A method,according to claim 1, further comprising periodically providing to eachof said control systems information which is a function of themeasurement of the total instantaneous consumption of electric energy bysaid appliances.
 10. A method, according to claim 1, further comprisingproviding to each of said control systems information which is afunction of the maximum power available from said source, and causingeach control system to adjust the load presented to said power source byits corresponding appliance as a function of said maximum availablepower.
 11. A method, according to claim 10, further comprising storingin each of said electronic control systems, a magnitude which is afunction of the maximum available power from the source.
 12. A method,according to claim 10, further comprising transmitting to each of saidelectronic control systems a magnitude which is a function of theavailable maximum power from the source, and causing each of saidcontrol systems to store said transmitted magnitude.
 13. A method,according to claim 1, further comprising storing in each of said controlsystems information indicative of the priority of the appliancecorresponding to said control system relative to priorities of other oneof said appliances.
 14. A method, according to claim 13, furthercomprising causing each one of the electronic control systems totransmit to each other one of the electronic control systems informationindicative of the current energy consumption of said one control systemand the priority assigned to the appliance corresponding to said onecontrol system.
 15. A method, according to claim 13, further comprisingassigning a maximum priority to an appliance connected to the source ofpower which does not have a corresponding electronic control system. 16.A method, according to claim 1, further comprising exchanginginformation between each of the control systems and the measuringdevice.
 17. A method, according to claim 16, wherein the information istransmitted and received on the electrical network.
 18. A method,according to claim 16, further comprising performing said informationexchange among the control systems and measuring device in accordancewith a predetermined communication protocol.
 19. A method, accordingclaim 1, wherein the measuring device comprises, ammeter means formeasuring the electrical current output of said source of power,voltmeter means for measuring the voltage across said source of power,control logic circuitry means operatively connected to said ammetermeans and said voltmeter means for producing signals indicative of thepower output of said source of power to said appliances, and interfacemeans operatively connected between said control logic circuitry meansfor enabling the exchange of information between said control logiccircuitry means and said electronic control systems.
 20. A method,according to claim 19, wherein the measurement of instantaneous totalconsumption of electrical energy is done by said control logic circuitrymeans as a function of information supplied by said ammeter means andsaid voltmeter means.
 21. A method, according to claim 20, wherein themeasurement of instantaneous total consumption of electrical energy isdone by said control logic circuitry means as a further function of themagnitude of the phase angle between the voltage and the current, thephase angle being determined from by measuring the time elapsed betweena time at which the voltage is zero and a time at which the current iszero.
 22. A method, according to claim 1, wherein the measuring devicecomprises, receiver means for receiving power consumption informationfrom a supplier of electrical energy to the source of power.
 23. Amethod, according to claim 22, further comprising causing said measuringdevice to transmit the current time, whereby at least one of saidcontrol systems can manage the power consumption of its respectiveappliance as a function of time, without need for a local clock situatedat said one control system and its corresponding appliance.
 24. Amethod, according to claim 1, further comprising measuring theinstantaneous total consumption of electrical energy from the powersource with a measuring device by continuously measuring and summing thepower consumed by each of the appliances.
 25. Apparatus for managing thepower consumption of appliances on a powered network, comprising,measuring means operatively connected to said network for transmittinginformation indicative of the total instantaneous consumption of poweron said network, and a plurality of electronic control systems in one toone correspondence with a plurality of said appliances, each of saidcontrol systems including receiver means for receiving from saidmeasuring means said information indicative of the total instantaneousconsumption of power on said network, maximum power storage means forstoring information indicative of the maximum power available on thenetwork, comparison means responsive to said receiver means and to saidmaximum power storage means for comparing the instantaneous consumptionof power on said network with the maximum power available on thenetwork, and control means responsive to said comparison means foradjusting the load presented by said corresponding appliance to saidnetwork in response to said comparison means.
 26. Apparatus, accordingto claim 25, wherein said maximum power storage means comprises meansfor remotely receiving said information indicative of the maximum poweravailable on the network.
 27. Apparatus, according to claim 25, whereinat least one of said control systems further comprises sensor means fordetecting an operating condition of its respective appliance andtransmitting information indicative thereof to another one of saidcontrol systems.
 28. Apparatus, according to claim 25, wherein each ofsaid control systems further comprises priority means for storinginformation indicative of the priority of its corresponding appliancerelative to other appliances on the network, said comparison means beingfurther responsive to said control means for adjusting the loadpresented by said corresponding appliance to said network.
 29. Apparatusfor managing a plurality of electronic appliances comprising a pluralityof electronic control systems in one to one correspondence with saidplurality of electronic appliances, at least a first one of said controlsystems having sensor means for detecting an operating condition of itsrespective appliance and transmitting information indicative thereof toa second one of said control systems, said second one of said controlsystems having receiver means for receiving said information from saidsensor means and control means responsive to said receiver means forcontrolling the operation of its respective appliance.